Chapter 6 J: Caries Etiology And Evolution Flashcards
Dental caries is an ___ disease in which 3 factors interact in a way that increases demineralisation of the tooth?
Ecological, diet, host, and microbial flor
The difference in occurrence of dental caries in different individuals of same age, sex, race and geographic area, diet, and similar living condiitons is because of?
Various factors that manipulate the etiology of caries such as?
1. Host (Tooth)
2. Substrate (environmental factors)
3. Microorganisms
4. Time period
Host (tooth): 3 factors:
- Variations in morphology
- Composition
- Position
Lack of enamel maturation or the presence of developmental defects in enamel increase:
Plaque retention
Bacteria colonisation
And increase in caries risk
Examples of lack of maturation of enamel?
Fluorosis, enamlogenesis imperfecta
In what areas of the tooth is there an increment of caries risk?
Deep and narrow occlusal fissures, deep lingual or buccal pits, and enamel hypoplasia
Is there a difference in the chemical composition of carious and sound enamel in contents of calcium, phosphorus, magnesium, and carbon ?
No but there is in fluoride (less in carious dentin)
How can tooth position affect the initiation of dental caries?
In a tooth is out of position, rotated, in any abnormal position
Because it’s harder to clean, plaque retentive factor, retains more food and debris
Other external factors related to the host that increase caries risk?
Retainer wear, orthodontic treatment, deficient obturations, and prosthetic clamps
What is the body’s natural protective mechanism against decay?
Saliva
The pellicle is?
The protective layer formed by deposition of salivary proteins onto the tooth surface that help enamel against acid dissolution
Plaque attaches deeper than the pellicle
Functions of Salvia are:
- mechanical scavenging: auto cleasis
- buffering capacity
- decrease of enamel solubility
- antibacterial effect
MAD B
What ions present in saliva help in remineralisation
Calcium and phosphate
Which factors affect the susceptibility for caries:
- composition of saliva: saliva may affect caries rate by influencing bacteria, immune status, plaque formation
- saliva has a very important role in the balance between demineralisation and mineralisation
What determines whether dental caries occur or not?
The balance between remineralisation and demineralisation
What did primitive men eat and how did it help with the prevention of caries?
They ate rough and raw unrefined foods that had self cleaning capacity
To cause demineralisation of the dental enamel, it’s essential for fermentable carbohydrates and plaque to be present on the tooth surface for?
A mínimum time to be metabolised by oral bacteria to produce acid
The acids produced by these fermentable carbohydrates cause?
A rapid drop in plaque pH to a level which results in demineralisation of the tooth structure
How long does it take for the pH to return to normal (remineralisation)?
30-60 mins
Stephan curve:
- quick drop: fermentation of carbohydrates (Demineralisation)
- gradual return: buffers present in plaque and saliva (Remineralisation)
- under the line: can have caries
- above 5.5 is good
There’s reduced caries activity with?
Sugar alcohols sweetness, sorbitol and xylitol
Which carbohydrates cause more caries?
Low molecular weight carbohydrates since they diffuse rapidly into plaque and are metabolised quickly by bacteria as opposed to complex carbohydrates because they’re not completely digested in the mouth
The most cariogenic sugar is?
Sucrose because streptococcus mutans use it to produce glucan (Extracellular polysaccharide that helps in adhesion to teeth)
Quantity or frequency of carbohydrates ?
Frequency
Deficiency of vitamin A causes?
Nothing
Deficiency of vitamin B causes?
Its deficiency may exert a caries protect influence (important factor for acidogenic flor growth)
B6: anti cares agent (factor for non cariogenic organisms growth)
Deficiency in vitamin C causes?
Its required for normal health of gingiva
Deficiency of vitamin D causes?
Helps in normal development of teeth, deficiency : hypoplasia
Do dental caries occur if there’s no bacteria in the mouth ?
No
Streptococcus mutans:
- gram +
- acidophilus
- acidogenic
- found in fissures and inter proximal sulcus
- enamel caries
Lactobacillus sp:
- gram +
- acidophilus
- acidogenic
- grows better in anaerobic conditions, deep dentin
Actinomyces spp:
- gram +
- acidogenic
- sub gingival plaque and root caries
- in periodontitis
Which bacteria is most commonly associated with dental caries?
Streptococcus
